1. Field of the Invention
The present invention generally relates to a collimating lens, and more particularly to a collimating lens with a diffraction lens.
2. Description of Related Art
A collimating lens is an optical device that aligns light beams in a specific direction to make collimated light or parallel rays. Accordingly, light does not disperse with distance, or at least, will disperse minimally. The collimating lens may be used with a light source such as a laser diode.
A conventional collimating lens may consist of a mould-made curved lens composed of glass. As a result, cost is high and overall dimension is large. Moreover, the conventional collimating lens possesses at least one convex surface, which makes assembling the collimating lens difficult.
For the foregoing reasons, a need has arisen to propose a novel collimating lens to eliminate drawbacks of the conventional collimating lens.